xdg-shell: Make xdg_popup non-grabbing by default

Turn xdg_popup into plain temporary child surfaces without any grabbing
or mapping order requirements by default.

In order to create grabbing popup chains, a new request 'grab' is
introduced which enables more or less the same semantics and
requirements as xdg_popup previously had related to grabbing, stacking
and mapping order.

This enables using xdg_popup for creating tooltips and other user
interface elements that does not want to take an explicit grab.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Signed-off-by: Mike Blumenkrantz <zmike@samsung.com>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>
Acked-by: Quentin Glidic <sardemff7+git@sardemff7.net>

1 files changed, 73 insertions, 42 deletions

diff --git a/unstable/xdg-shell/xdg-shell-unstable-v6.xml b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
index e4d552c..0771668 100644
--- a/unstable/xdg-shell/xdg-shell-unstable-v6.xml
+++ b/unstable/xdg-shell/xdg-shell-unstable-v6.xml
@@ -164,16 +164,11 @@
 	This creates an xdg_popup object for the given xdg_surface and gives the
 	associated wl_surface the xdg_popup role.
 
-	This request must be used in response to some sort of user action like a
-	button press, key press, or touch down event.
-
 	See the documentation of xdg_popup for more details about what an
 	xdg_popup is and how it is used.
       </description>
       <arg name="id" type="new_id" interface="zxdg_popup_v6"/>
       <arg name="parent" type="object" interface="zxdg_surface_v6"/>
-      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat of the user event"/>
-      <arg name="serial" type="uint" summary="the serial of the user event"/>
       <arg name="x" type="int"/>
       <arg name="y" type="int"/>
     </request>
@@ -675,46 +670,30 @@
 
   <interface name="zxdg_popup_v6" version="1">
     <description summary="short-lived, popup surfaces for menus">
-      A popup surface is a short-lived, temporary surface that can be
-      used to implement menus. It takes an explicit grab on the surface
-      that will be dismissed when the user dismisses the popup. This can
-      be done by the user clicking outside the surface, using the keyboard,
-      or even locking the screen through closing the lid or a timeout.
-
-      When the popup is dismissed, a popup_done event will be sent out,
-      and at the same time the surface will be unmapped. The xdg_popup
-      object is now inert and cannot be reactivated, so clients should
-      destroy it. Explicitly destroying the xdg_popup object will also
-      dismiss the popup and unmap the surface.
-
-      Clients will receive events for all their surfaces during this
-      grab (which is an "owner-events" grab in X11 parlance). This is
-      done so that users can navigate through submenus and other
-      "nested" popup windows without having to dismiss the topmost
-      popup.
-
-      Clients that want to dismiss the popup when another surface of
-      their own is clicked should dismiss the popup using the destroy
+      A popup surface is a short-lived, temporary surface. It can be used to
+      implement for example menus, popovers, tooltips and other similar user
+      interface concepts.
+
+      A popup can be made to take an explicit grab. See xdg_popup.grab for
+      details.
+
+      When the popup is dismissed, a popup_done event will be sent out, and at
+      the same time the surface will be unmapped. See the xdg_popup.popup_done
+      event for details.
+
+      Explicitly destroying the xdg_popup object will also dismiss the popup and
+      unmap the surface. Clients that want to dismiss the popup when another
+      surface of their own is clicked should dismiss the popup using the destroy
       request.
 
       The parent surface must have either the xdg_toplevel or xdg_popup surface
       role.
 
-      Specifying an xdg_popup for the parent means that the popups are
-      nested, with this popup now being the topmost popup. Nested
-      popups must be destroyed in the reverse order they were created
-      in, e.g. the only popup you are allowed to destroy at all times
-      is the topmost one.
+      A newly created xdg_popup will be stacked on top of all previously created
+      xdg_popup surfaces associated with the same xdg_toplevel.
 
-      If there is an existing popup when creating a new popup, the
-      parent must be the current topmost popup.
-
-      A parent surface must be mapped before the new popup is mapped.
-
-      When compositors choose to dismiss a popup, they will likely
-      dismiss every nested popup as well. When a compositor dismisses
-      popups, it will follow the same dismissing order as required
-      from the client.
+      The parent of an xdg_popup must be mapped (see the xdg_surface
+      description) before the xdg_popup itself.
 
       The x and y arguments passed when creating the popup object specify
       where the top left of the popup should be placed, relative to the
@@ -723,11 +702,13 @@
 
       The client must call wl_surface.commit on the corresponding wl_surface
       for the xdg_popup state to take effect.
-
-      For a surface to be mapped by the compositor the client must have
-      committed both the xdg_popup state and a buffer.
     </description>
 
+    <enum name="error">
+      <entry name="invalid_grab" value="0"
+	     summary="tried to grab after being mapped"/>
+    </enum>
+
     <request name="destroy" type="destructor">
       <description summary="remove xdg_popup interface">
 	This destroys the popup. Explicitly destroying the xdg_popup
@@ -738,6 +719,56 @@
       </description>
     </request>
 
+    <request name="grab">
+      <description summary="make the popup take an explicit grab">
+	This request makes the created popup take an explicit grab. An explicit
+	grab will be dismissed when the user dismisses the popup, or when the
+	client destroys the xdg_popup. This can be done by the user clicking
+	outside the surface, using the keyboard, or even locking the screen
+	through closing the lid or a timeout.
+
+	If the compositor denies the grab, the popup will be immediately
+	dismissed.
+
+	This request must be used in response to some sort of user action like a
+	button press, key press, or touch down event. The serial number of the
+	event should be passed as 'serial'.
+
+	The parent of a grabbing popup must either be a xdg_toplevel surface or
+	another xdg_popup with an explicit grab. If the parent is another
+	xdg_popup it means that the popups are nested, with this popup now being
+	the topmost popup.
+
+	Nested popups must be destroyed in the reverse order they were created
+	in, e.g. the only popup you are allowed to destroy at all times is the
+	topmost one.
+
+	When compositors choose to dismiss a popup, they may dismiss every
+	nested grabbing popup as well. When a compositor dismisses popups, it
+	will follow the same dismissing order as required from the client.
+
+	The parent of a grabbing popup must either be another xdg_popup with an
+	active explicit grab, or an xdg_popup or xdg_toplevel, if there are no
+	explicit grabs already taken.
+
+	If the topmost grabbing popup is destroyed, the grab will be returned to
+	the parent of the popup, if that parent previously had an explicit grab.
+
+	If the parent is a grabbing popup which has already been dismissed, this
+	popup will be immediately dismissed. If the parent is a popup that did
+	not take an explicit grab, an error will be raised.
+
+	Clients will receive events for all their surfaces during this grab
+	(which is an "owner-events" grab in X11 parlance). This is done so that
+	users can navigate through submenus and other "nested" popup windows
+	without having to dismiss the topmost popup.
+      </description>
+
+      <arg name="seat" type="object" interface="wl_seat"
+	   summary="the wl_seat of the user event"/>
+      <arg name="serial" type="uint" summary="the serial of the user event"/>
+    </request>
+
     <event name="popup_done">
       <description summary="popup interaction is done">
 	The popup_done event is sent out when a popup is dismissed by the